Acquisition (Details 2) (Waste heat recovery generator)	0 Months Ended	1 Months Ended	12 Months Ended
	Feb. 01, 2010 kW	Oct. 31, 2010 kW	Mar. 31, 2013 kW
Original Equipment Manufacturer (OEM) Agreement
Maximum capacity of applications for which zero emission generators can be exclusively sold			500
CPS
Original Equipment Manufacturer (OEM) Agreement
Capacity of generator (in kW)	125	125
Maximum capacity of applications for which zero emission generators can be exclusively sold			500